Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!decvax!mcnc!gatech!bloom-beacon!husc6!linus!philabs!gcm!dc
From: dc@gcm (Dave Caswell)
Newsgroups: comp.databases
Subject: Re: Database implementation/theory issues?
Message-ID: <415@white.gcm>
Date: 27 Feb 88 22:17:33 GMT
References: <33671UH2@PSUVM> <232@cullsj.UUCP> <725@smidefix.liu.se>
Reply-To: dc@white.UUCP (Dave Caswell)
Organization: Greenwich Capital Markets, Greenwich, CT
Lines: 33

In article <725@smidefix.liu.se> gorry@smidefix.liu.se (Goran Rydquist) writes:
)
)The greatest evil in today database theory is the unquestioned (?) assumption
)that the data model must be based on records. This is true for all three of
)the accepted and currently used data models, namely the hierarchical, the
)network and the relational models.
)
)I quote:
)	Models which provide additional file structure around the records 
)	(eg sequencing, hierarchies, CODASYL networks) overcome some of the
)	functional limitations of records. None of the overcome all the
)	limitations. Furthermore, by building on top of record structures,
)	they retain all the underlying ambiguities. In some cases, they simply
)	add more options for representing something which could already be
)	represented in several ways in record structure. 
)[W. Kent, Limitations of Record-Based Information Models", ACM Transactions on
)Database Systems, vol 4, no 1, pp 107-131, March 1979]
)
)I would like to hear comments, historical motivations, views etc.


I'm not sure how to respond to this.  You say that something is the greatest 
evil without giving any reasons why.  What are the functional limitations of 
records?  What would like to order by (use for sequencing) if not a field in
a record?  Do records have a natural sequencing apart from their contents?

You say "In some cases, they simply add more options ..".   Again I ask what
do you want to represent that can not be represented in records?   What does 
"adding file structure" or files in general have to do with data models?
What are all the underlying ambiguities?

In twenty-five pages the author must have had some arguments, why don't you 
summarize them?